DNA polymerase E is a highly processive enzyme that continuously synthesizes the leading strand. Its processivity results from its interaction with RFC clamp loader and trimeric PCNA processivity clamp

TLS Online TPP Program

#Id: 8272

#Unit 1. Molecules and their Interaction Relevant to Biology

A hydrogen bond is an intermolecular force (IMF) that forms a special type of dipole-dipole attraction when a hydrogen atom bonded to a strongly electronegative atom exists in the vicinity of another electronegative atom with a lone pair of electrons.

TLS Online TPP Program

#Id: 8273

#Unit 1. Molecules and their Interaction Relevant to Biology

Hydrogen bonds are generally stronger than ordinary dipole-dipole and dispersion forces, but weaker than true covalent and ionic bonds.

TLS Online TPP Program

#Id: 8274

#Unit 1. Molecules and their Interaction Relevant to Biology

Two Requirements for Hydrogen Bonding:

First molecules has hydrogen attached to a highly electronegative atom (N, O, F) called as (hydrogen bond donor)

Second molecule has a lone pair of electrons on a small highly electronegative atom (N, O, F) called as (hydrogen bond acceptor)

TLS Online TPP Program

#Id: 8275

#Unit 1. Molecules and their Interaction Relevant to Biology

Since the hydrogen donor (N, O, or F) is strongly electronegative, it pulls the covalently bonded electron pair closer to its nucleus, and away from the hydrogen atom.

The hydrogen atom is then left with a partial positive charge, creating a dipole-dipole attraction between the hydrogen atom bonded to the donor and the lone electron pair of the acceptor. This results in a hydrogen bond.

TLS Online TPP Program

#Id: 8276

#Unit 1. Molecules and their Interaction Relevant to Biology

TLS Online TPP Program

#Id: 8277

#Unit 1. Molecules and their Interaction Relevant to Biology

For maximum stability, the donor pair (AH) and the acceptor (B) are usually colinear (that is, i., AHB = 180°), but deviations of up to 30° are known.